This invention relates to the field of peristaltic compressors. This type of compressor uses the principle of peristaltic pumps, wherein a set of rollers presses a flexible tube and upon their rotation around an axis, causes the fluid which is contained in the tube to flow forwards.
Peristaltic compressors of the prior art mainly operate under pressure. Under vacuum pressure, the tube in which the fluid flows, tends to be squeezed, preventing the pump from operating. As an example of a peristaltic pump known from the prior art, French Patent 2640698 describes a peristaltic pump including several pinch valves with sleeves pinched by a pressurized fluid. Its body consists of at least two modules placed in series and each including a sleeve. The ends of each sleeve are sealably secured to the edges of the suction and discharge port of each module. The module located on the inlet side of the pump plays the role of a suction valve. The module located on the outlet side of the pump plays the role of a discharge valve.
European Patent 869283 relates to a peristaltic pump including a rotor preferably with two or three rollers which roll against at least one tube containing the liquid to be pumped. Compression of the tube presses the rollers against the circular peripheral surface of a vibrating central stator in the shape of a disc or ring, which guides the rollers and causes them to rotate. The stator is put into vibration by piezoelectric means and vibrates by expansion in its radial plane according to a progressive wave. The chassis of the rotor is without any central shaft.
German Patent 370124 describes a pump with a flexible core comprising:
a) a casing including:
a1) a suction manifold and a compression manifold,
a2) a peripheral wall which, at least in a squeezing area located along the long linking part between the suction manifold and the compression manifold, has the shape of a circular section cylinder and
a3) a plane front wall and a plane rear wall,
b) a flexible tube which runs from the suction manifold to the compression manifold along the peripheral wall into the squeezing area and the periphery of which essentially corresponds to double the distance between the front wall and the rear wall,
c) a rotor with its rotation axis coinciding with the axis of the squeezing area of the peripheral wall and with a circular section cylinder shape, and which includes at least two collapsible bodies symmetrically positioned relatively to a point and which rotates in such a way that each collapsible body squeezes the flexible tube from the suction manifold area to the compression manifold area.
A separator device sealably isolates a suction area, i.e., a portion of the inside of the pump wherein vacuum pressure prevails during the pumping, from a compression area in which no vacuum pressure prevails.
The separator device includes a device providing a seal at the rotor and an elastic gasket. The device providing the seal at the rotor, is secured to the rotor and sealably separates the latter from the front wall and the rear wall.
U.S. Pat. No. 5,049,048 describes a tubular pump including a case with a discharge fitting and a suction fitting. A first tube is connected to the discharge and suction fittings and laid out against the inner wall of the case. Compression components may move along the tube in such a way that said tube may be compressed by each of the compression components from the direction of the suction fitting to the direction of the discharge fitting. The pump includes at least a second elastically deformable tube with one of its ends ending in the inner portion of the case whereas its other end ends outside said case.
U.S. Pat. No. 5,261,793 relates to a compressor with which very low pressures may be achieved by selection of a suitable tube (sufficiently small diameter, sufficiently thick wall) in order to prevent its flattening (Col. 5, lines 10-12). This constraint on the selection of the tube is a priori a nuisance for application to the polarized gas: a small section increases the surface/volume ratio and increases relaxation for the polarized gas; a small section reduces the pump flow rate, all things being equal for that matter.
In addition, it is important to be able to select the type of material for the tube according to its compatibility properties with the application to polarized gas, without being restricted to the stiffest tubes. French Patent 1394047 A describes a compressor wherein both evacuation of the pump body and its driving by a peristaltic motor appear. On the other hand, this is not a peristaltic pump, as the fluid is contained not in a tube but in a deformable compartment sealed by rubber membranes. Such a compressor is totally unsuitable for producing a compressor polarized gas.
This invention relates to a peristaltic compressor suitable for relaxation-free compression of polarized gas including a pumping rotor driven by a motor provided with a plurality of rollers, and at least a tube, wherein the rotor and the tube(s) is(are) placed in a depressurized chamber having a lower pressure than atmospheric pressure, and wherein the motor is formed by at least one tube fed by a pressurized fluid, driving into rotation a peristaltic rotor provided with rollers, coupled with the pumping rotor.
This invention also relates to a system for producing hyperpolarized helium by optical pumping including a peristaltic compressor formed with a magnetic parts exclusively and including a rotor driven by a motor provided with a plurality of rollers, and at least one tube, wherein the rotor and pumping tubes are located in a depressurized chamber inside which has a pressure lower than atmospheric pressure.